1. Field of the Invention
This invention relates to rotary edgers, trimmers or the like which employ a flexible cord for cutting grass, weeds and other vegetables in a flail-like manner. Typically these cutters are used in areas in which vegetation is somewhat inaccessible to apparatus employing rigid cutting blades or where there is a risk that rigid blades may throw items concealed by the vegetation.
2. Description of the Prior Art
Generally, such trimmer devices include a head member suspended from an upwardly disposed elongated handle. The head member has a housing that contains an electric motor or gasoline engine which rotates a downwardly directed shaft at high speed. A cutting cord is associated with the shaft, and extends perpendicularly therefrom by centrifugal force to define a cutting plane. The cord is fabricated of a material such as nylon monofilament which is flexible to the extent that it is substantially incapable of causing damage or injury when impacted against persons, animals, trees, etc.
Most embodiments of such trimmer devices include means for detachably holding a supply of cord so that the rotated extremity of the cord may be replaced after wear or breakage resulting from impact during use. The supply of additional cord is generally a continuous coil length stored upon a flanged spool of standardized construction and generally mounted upon said shaft. Fresh cord may be tangentially drawn from the spool to restore the working length, namely the length between the spool and the free extremity of the cord.
In the course of prolonged use of a rotary trimmer device, the significant weight of the apparatus will cause the operator to become arm-weary. To overcome this problem, the placement of wheels below or adjacent the head member has been proposed in U.S. Pat. No. 4,914,899; 4,936,886; 4,981,012 and 5,095,687.
Although wheels permit the apparatus to be rolled upon the ground, the wheels add further weight and also inhibit movement in the transverse direction, namely the direction orthogonal to the plane of rotation of the wheels. Such transverse movement is essential because, in much of the motion of the apparatus, it is swung in an arc-like path centered about the user. Because wheels could be impacted by the rotary string, they must be spaced far from the center of rotation. This in turn requires that the housing be of longer size, with attendant increased weight.
The control of cutting height, namely the elevation of the apparatus above the ground, is important in producing a uniform trimming job. Most trimmer devices have no provision for accurate control of cutting height, such factor being dependent upon the expertise of the operator.
It is therefore an object of the present invention to provide an attachment device for a rotary trimmer whereby said trimmer can be operated with less effort.
It is another object of this invention to provide a device as in the foregoing object which provides height control during use of the trimmer.
It is a further object of the present invention to provide a device of the aforesaid nature which does not impede transverse movement of the trimmer in an arcuate path centered upon the user.
It is a still further object of this invention to provide a device of the aforesaid nature which adds little weight to the trimmer and requires substantially no modification of the trimmer.
It is yet another object of the present invention to provide a device of the aforesaid nature which is easily installable, durable, and amenable to lost cost manufacture.
These and other beneficial objects and advantages will be apparent from the following description.